HIERARCHICAL STRUCTURE AND EVOLUTION

Nlklas Luhmann falls directly into that category of sociologists we call "functionalists", though he prefers the term "neo-functionalist" to separate his theories from those of Talcott Parsons. Functionalist approaches to evolution theory have been particularly successful In developing historical descriptions of evolutionary systems, but have traditionally failed when it comes to generality. The reason for this lies In the limitations of the functional approach, not In the Imagination or abilities of the functionalist theorists. Nlklas Luhmann has broken with the traditional functionalist approach in a number of areas, but fundamental among them is that he rejected the concept of a function as a relationship between a problem and Its resultant solution. instead, he referred to the relationship that inheres between a problem or a number of related problems and the range of their possible solutions. This opened his approach up to an examination of the Imaginable, the unexpected, and the possible though unimagined as well as historically documented directions of evolutionary change.

However, in his attempt to accomplish this he was forced to abandon functionalism In favor of cybernetics. This led directly to a problem that Pioggl misunderstood as a contradiction in Luhmann's approach. In his introduction to Trust and PowerPioggl expressed It as the problem of complexity. In this case Luhmann's habit of constantly Insisting that the formation of social systems Is accomplished by a reduction of complexity through selection from a surplus of possibilities while at the sane time claiming that the act of formation increases complexity with the result that successful systems are so because they are able to match the complexity In their environment. Then again, he made systems islands of lower complexity in a field (environment) of higher complexity. It Is my contention that while Luhmann recognized an extremely Important property of complex systems he was not able to express it in non-contradictory terms. This was because he lacked a clear and unambiguous theory of complexity. By applying theories of complex systems developed by Herbert Simon, Howard Pattee, Robert Rosen, and others, we can dispel the dilemma In Luhmann's approach to complexity while demonstrating the value these theories have for developing understandable descriptions of social structures, that is descriptions which avoid the equivocation Luhmann's approach leads to. Luhmann's cybernetic description of complexity was essentially the same as the meaning of the term "Variety" In W. Ross Ashby's theory of "Requisite Variety." This theory stated that in order for one system to control another the controlling system must contain at least as much variety as the system being controlled. To put it in simpler terms, for any system to control another it must have a relevant response for every action that the controlled system can possibly make. If there existed a one-on-one mapping relationship between the two systems then they would essentially be parts of the same system. One system must have at least some characteristics which are not Included In the other In order for It to be a different system and this added variety must then be In the controlling system or else It would not have sufficient variety to control the other.

Complexity In these terms is the totality of the systems variety. Modern systems theories, such as operations research, cybernetics, Information theory etc. have been developed to solve problems In the control of directed, deterministic, man-made systems. While the purport of Ashby's law of requisite variety Is simply that the variety In a controlling system must be at least as great as that In the system under control, natural systems, and this is particularly true for social systems, are awash in a sea of excess variety. This, of course Is exactly the problem that Luhmann Is trying to describe. The fundamental question now becomes, how do they exist other than at the whim of their environment? The answer, however, Is not very readily apparent under mechanisms developed for simpler deterministic systems. In particular, processes cyberneticians have developed for reducing variety in order to maintain control of simple deterministic systems are not valid when the variety exceeds that which can be designed Into man-made environments,

Thus complexity, In Ashby's sense, Is an expression of the interconnections among the system's variety. The richer the pattern of Interconnections, the higher the level of complexity. Luhmann limited his use to the variety of social decisions. As he put it, "By complexity we mean the number of possibilities from which, through experience and action, we can choose--either through structural reduction or through conscious decision making". Nevertheless, dealing with complexity on terms which Ignore properties that delineate complex interconnections from masses of simple variety results in an approach which treats complexity and variety as essentially redundant terms. As an Illustration, Herbert Simon, In his parable of the ant In Sciences of the Artificial, maintained that the complexity evident In the trail of an ant crossing a wind-swept beach to his nest was a complexity In the beach, that in fact the ant as a behaving system Is quite simple. But, if we look at the beach, we do not see complexity, what we do see is a great amount of variety. For example, the ant comes upon a pebble It must go around. It might be that going clockwise Is a better choice because It leads to a smoother path. However, the ant cannot know this. Its knowledge consists simply of an unerring sense of direction toward home. Thus, It Is not aware of any relationship that might exist between the route around the pebble and further Impediments. Its choice is not complex at all, it Is a simple choice between two arbitrary directions. Of course, there are interconnections between the various obstacles that lie on the beach between the ant and its destination but these, being beyond the scope of knowledge of the ant, are Irrelevant to the problem of meaningful choice. If we want to learn how complexity plays an important role In this scenario we must have a different description, one that recognizes the unique patterns of Interconnections that exist In complex systems.

We can find this description of complexity In Simon's parable of two watchmakers in "The Architecture of Complexity." Tempus and Hora, as Simon explained, were both watchmakers whose work was prized in their community. While Tempus assembled his watches as a single assembly, Hora built his up out of many sub-assemblies. Because of their popularity both were constantly being interrupted by phone calls. the result Is that before Tempus could complete a watch he had to put It down to answer the phone and It promptly fell apart. Hora's sub-assemblies, on the other hand, could be completed between calls and as a result the most he could lose In the case of Interruption was a tenth of a watch. Obviously Hora prospered having an ample supply of watches while Tempus failed due to a lack of complete assemblies. This supplies the underlying strata we will use to develop the mechanisms we need to clear away the ambiguities caused by Luhmann's use of both "Complexity" and "Variety" In terms which portray them In redundant roles. The parable of the watchmakers presents a special hierarchical structure In which the elements of each level are systems In their own right which are interconnected such as to emerge Into a higher level, which then becomes one element In a level above that. This is the fundamental characteristic of the structure of complex systems. We can begin here to develop a set of properties Inherent In complexity that make It an effective mechanism for the development of self-controlling systems under conditions of excess variety and consequently the underlying directive force in evolution.

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